Apparatus for use in the correction of maxillary and premaxillary conditions in infants

ABSTRACT

An arch alignment appliance for use in the correction of the maxillary and premaxillary deformity in infants with bilateral cleft lip and palate is achieved through the application of an intra-oral maxillary expansion and premaxillary retraction device capable of extra-oral operation. A screw mechanism is provided for expansion of the maxillary segments and for retraction of the premaxillary segments. Mucosal tissue damage is avoided.

United States Patent [191 Georgiade et a].

APPARATUS FOR USE IN THE CORRECTION OF MAXILLARY AND PREMAXILLARYCONDITIONS IN INFANTS Inventors: Nicholas G. Georgiade, Durham;

Ralph A. Latham, Chapel Hill, both of NC.

University of North Carolina, Chapel Hill, NC. by said Ralph A. LathamFiled: Nov. 20,1974

Appl. No.: 525,508

Assignee:

US. Cl. 128/76 R; 128/17 Int. Cl. A61F 5/00 Field of Search 128/76, l2,17, 20, 345;

References Cited UNITED STATES PATENTS Davis 128/17 Dec. 23, 19752,587,245 2/1952 Terre 128/12 3,241,550 3/1966 Gelarie 128/12 3,454,0017/l969 Stockfisch 128/76 R Primary Examiner-Richard A. Gaudet AssistantExaminer.l. Yasko Attorney, Agent, or Firm-B. B. Olive [57] ABSTRACT Anarch alignment appliance for use in the correction of the maxillary andpremaxillary deformity in infants with bilateral cleft lip and palate isachieved through the application of an intra-oral maxillary expansionand premaxillary retraction device capable of extraoral operation. Ascrew mechanism is provided for expansion of the maxillary segments andfor retraction of the premaxillary segments. Mucosal tissue damage isavoided.

7 Claims, 7 Drawing Figures US. Patent Dec. 23, 1975 FIGK APPARATUS FORUSE IN THE CORRECTION OF MAXILLARY AND PREMAXILLARY CONDITIONS ININFANTS CROSS-REFERENCE TO THE. RELATED APPLICATION This applicationrelates to and constitutes an improvement over copending applicationSer. No. 489,813 entitled Apparatus For Use In Treatment Of TheBilateral Cleft Lip And Palate Condition In Infants. of which one of theco-inventors of the present application was sole inventor.

BACKGROUND OF THEINVENTION cations, Ser. No. 489,813 and to whichreference may.

be made. For immediate reference to. this invention much of suchdiscussion will be repeated here.

The markedly protruding premaxilla and its positioning in the maxillaryarch in severe bilateral clefts has been a topic of varied discussions,publications and devices for many years. Heretofore, external tractionhas been cumbersome, difficult to maintain and, if applied with too muchtension, has caused loss of the soft tissue elements of the philtrum.

Various surgical reduction methods and devices for sectioning andrepositioning the vomer are available; however, this has led to anunstable premaxillary segment in some patients and eventual tilting ofthe premaxillary segment lingually with resultant malposition of thepermanent incisor teeth in others. Decreased growth of the premaxillarysegment has also been a consideration following wedge resection of aportion of the vomerjThe surgical lip adhesion" technique, described forgradual retro-positioning of the premaxilla, necessitates one or twoadditional operative procedures prior to the actual lip repair and isunreliable.

A method, which introduces an intra-oral approach was introducedbyone ofthe co-inventors hereof, Dr. Nicholas G. Georgiade of Duke UniversityMedical Center, Durham, North Carolina, in 1968. This utilizes Kirschnerpins which are inserted through the cheeks, under local anesthesia, inthe posterior maxillary area distal to the tooth follicles; The excessKrichner wire is then cut allowing sufficient wire to be present in eachbuccal sulcus so that the ends can be bent with thin nosed pliers in theshapes of hooks for rubber band fixation. If the patient has a completepalatal cleft associated with the premaxillary protrusion, rubber bandscan f be placed around the Kirschner wire half-way across the palatalcleft, facilitating their attachment to the anterior hooked wire. Thisinterior wire is inserted with a hand drill through the buccal aspectof-the' premaxilla in the region of the naso maxillary curves-Adequatelengths of wire are allowed to remain for hook formation at either endsimilar to that performed on the posterior maxillary wire. At thispoint, therubber maxillary segment also utilizes intra-oral traction topull the segment back into its proper relationship in the maxillaryaarch. Under local anesthesia, a Kirschner wire is inserted through onecheek just back of the maxilla. The wire is posterior to the location ofany possible tooth follicles.

. The patients mouth is opened to facilitate insertion 'of the wirewhich is then advanced until the correct alignment is attained, asjudged by its posistion just under the soft palate cleft. The Kirschnerwire then drilled laterally on through the opposite maxillarypterygoidarea until it is palpable in the opposite cheek. It is then cut as shortas possible, so that soft tissues of both cheeks will cover the wire. Astrip of Dacron is cut down the middle for half its length to create aY-shaped sling. One limb of the Y is threaded across theanteriorsuperior surface of the ptemaxilla subcutaneously, under theprolabium as close to the bone as possible and superior to the point ofthe most forward position of the segment. The second limb of the Y isplaced over the lower anterior (labial mucosal) aspect of the premaxillaand the, two previously separated ends are now sutured together withnylon. This makes it one continuous single band again, creating a lengthof Dacron on either side of the premaxilla, topull on a double slingover the bony segment. A standard rubber band is cut then at one end,threadedithrough each of the Dacron sling, and broughtaround theposterior Kirschner wire. The rubber band is now re-united to exertsufficient traction on the anterior segment, as judged by the tension onthe tied rubber band. The two cut ends of the rubber band are'suturedtogether with silk, using two small mosquito clamps to grasp them andadvance both of them until sufficient traction has beenobtained. Thistraction can beadjusted at the time of the lip repair to compensate forthe interval retropositioningof the premaxillary segment. 1

lntra-oral rubber bands have now been used in many patients and haveachieved what was expected of them, namely, a one-stage closure of thelip, and in some cases closure of the alveolar arch as well. However,

rubber bands lose their elasticity when used in the mouth and theirtension is reduced as retraction occurs. Ideally, they should bereplaced every two days. The continuousunremitting pull of rubber bandsdoes not represent. the, best means for obtaining the most rapidmovement when considered in terms of the collagen adjustment mechanisminvolved. A method and apparatus which accomplishes the desired movementin a series of steps, employing intermittent force IS thus much to bedesired.

substantial advance in the art. However, use of the prior apparatus hasindicated the need for improve ments directed to simplifying theconstruction, reducing irration to the mucosal tissues and improving theutility of the expansion portion of the apparatus as an bands areapplied and traction instituted, either directly posteriorly, or alongthe buccal aspect, depending on the cleft type. Twin oral pin fixationand traction independent device. Thus, the present invention has theseimprovements in mind as a general objective and further seeks to providefor the satisfactory management of not only the premaxillary segment butthe maxillary aleveolar arch as a whole.

SUMMARY OF THE INVENTION The apparatus of this invention, like that ofthe copending application, provides for incremental and intermittentretraction of the premaxilla and expansion of the maxilla, eitherindependently or together. In the embodiment disclosed, a pair ofintra-orally positioned control shafts, one within the other, extendoutward the length of the oral cavity. Each control shaft has a knobwhich can be rotated extra-orally to impart the desired expansion orretraction reaction within the cavity. An intra-oral universal jointreceives the shafts. The universal joint drives another threaded shaftwhich mounts a theaded block. The block slides in a housing. A pair ofpivotal arm members pivot on arm extensions of the housing and arepositioned by movement of the block which in turn is driven by theuniversal joint. These arm members, when the apparatus is in service,are secured, as with the apparatus of the copending application, to themaxilla segment through a pair of plates made integral with the lateralpalatal segments of the maxillae by appropriate staple pine. A saddle orU-shaped premaxillary yoke rides, through a screw arrangement, back andforth on the outer control shaft. The U-shaped yoke is secured by pinmeans to the premaxillary seg ment. Rotation of the outer control shaftcauses the U-shaped yoke to move in or out and effectively causes thepremaxillary bony segment to be repositioned to a more normal position.While being internally mounted within the patients mouth, the apparatusis externally activated and, if desired, either function, i.e.,retraction or expansion, may be obtained independent of the other. Whenthe retraction function is of primary interest, the inactive expansionmembers attached to the maxilla simply serve as an anchoring means andwhen expansion is of primary interest the mentioned yoke and outercontrol shaft act merely as a support for the inner controll shaft. Thementioned universal joint, block and housing arrangement reducesirritation of the mucosal tissue and provides a somewhat simplerconstruction as compared to the apparatus of the copending application.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the presentinvention apparatus for use in maxillary arch alignment with theapparatus being shown as it is installed in the mouth cavity for use.

FIG. 2 is a plan view of the apparatus of FIG. 1.

FIG. 3 is a side elevation view of the apparatus of the presentinvention.

FIG. 4 is a sectional view taken along line 44 of FIG. 2.

FIG. 5 is a perspective view of the screw block which is used in thepresent invention to activate the arm members shown in dashed lines.

FIG. 6 is a perspective view of a housing member which receives thescrew block and which also mounts the arm members.

FIG. 7 is a perspective view of the screw block equipped with a cap forturning with a mating wrench.

FIG. 8 is a fragmentary elevation view of the saddle arrangement.

DESCRIPTION OF-THE PREFERRED EMBODIMENT The improved intra oralmaxillary arch alignment apparatus of the present invention, generallydesignated by numeral 10, is illustrated as being adapted for extra-oralactivation.

A universal joint assembly 11 is integrally secured to one end of ashaft member l3 which itself is mounted within an externally threadedhollow shaft 12 in a manner enabling shafts 12 and 13 to each be rotatedindependent of the other, shaft 12 to be free to slide outwardly onshaft 13 and shaft 13 to extend, at its free end, beyond the end ofshaft 12. Shaft 12 has integrally secured to its extra-oral, free end aknurled knob portion 15 which as shown in FIG. 4 is secured to shaft 12he means of a set screw 16. A second knurled knob 18 is secured to theend of shaft 13 by set screw 19. A relatively easily compressed coilspring 17 mounts and is compressed between knobs l5 and 18 on thatportion of shaft 13 which extends beyond knob 15. Spring 17 thus pushesagainst knob 15 and in turn forces shaft 12 to slide inwardly on shaft13 and against the face of universal joint 11. Spring 17 shouldpreferably be at least slightly compressed when knobs 15 and 18 havetheir maximum spacing and should be compressible when knob 15 is turnedto decrease such spacing.

Prior to placing knobs 15 and 18 and spring 17 on their respectiveshafts, a saddle arrangement 20 is placed on shaft 12. Saddlearrangement 20 is composed of two U-shaped plates 20, 20 securedtogether by screws 54, 55. Plate 20 has a non-threaded hole 21 whichslides freely on shaft 12. Plate 20" has a threaded hole 21" which mateshole 21' and receives threaded shaft 12. Thus, when plates 20', 20" aresecured together to form saddle 20 and plate 20" is threadably mountedon shaft 12, saddle 20, if prevented from rotating, can be caused tomove back and forth along shaft 12 by turning knurled knob 15. AU-shaped yoke portion 22 of saddle arrangement 20 is adapted to bepinned to the premaxillary bone segment by a pin 53 passing through thesegment and through slots 23', 23" of yoke portion 22 of saddlearrangement 20. Pin 53 is positioned within slots 23', 23" by looseningscrews 54, S5 and sliding plate 20' as required after which screws 54,55 are tightened so that pin 53 becomes clamped between plates 20, 20".Such pinning by pin 53 thus fixes saddle 20 against rotation andprovides a fixed point to hold the premaxillary segment as it is beingretracted and it can be seen that the provision of knob 15 on shaft 12at its end opposite universal joint assembly 1 1 enables extra-oralrotation of shaft 12 to be translated into linear movement of the saddlearrangement 20 relative to shaft 12.

A T-shaped block 24, see FIG. 5, has a threaded passage 25 which extendscompletely through central body portion 26 of the block 24, Passage 25receives a relatively short threaded shaft 27. One end of shaft 27 isintegrally secured to the end of universal joint 11 which is oppositethe end of universal joint 11 that is integrally secured to shaft 13.Rotation of shaft 13 thus acts to rotate universal joint 11 whichrotates shaft 27 and causes block 24 to move him out depending on thedirection of rotation.

As best seen in FIG. 6, a housing member 30 is formed of sheet metal, orthe like, and has a base 31, back 32, top 33, and downwardly extendingside members 34, 35. A pair of integrally formed arms 36, 37

extend outwardly from base 31 and reside in a common plate parallel toand above base 31. Arms 36, 37 have respective apertures 38, 39. Base31, back 32, top 33, and sides 34 and 35, extending down apredetermineddistance as extensions of top 33, form a cavity 40 which is sufficientlylarge to house and slidably receive the previously mentioned T-shapedblock 24. A pair of crank arms 43, 44 mount respective pins 41, 42 whichrotate in the respective apertures 38, 39 thereby enabling arms 43, 44to pivot on the arms 36, 37. The outer ends 47, 48 of arms 43, 44"operate in a common plane parallel to and above base 31 of housing 30.The inner ends 45, 46 of arms 43, 44 occupy a lower common plane aboveand near base 31 and extend into housing through slots 47, 48 as bestseen in FIG. 6.

T-shaped block 24 is placed into housing 30 so that back 28 of block 24is substantially adjacent to back 32 of housing 30. At this point, arms43, 44 are rotated on pins 41, 42 until their respective inner ends 45,46 are extending into cavity and rest against front 29 of block 24. Aslater explained, the outer ends 47, 48 of arms 43, 44 are adapted toreceive, e.g., by molding thereto, a pair of plastic plates 49, 50 whichare secured to the maxillary segments and are molded to conform to thesegments.

The description will next refer to the insertion and operation of theintra-oral maxillary arch alignment apparatus 10 which is the subject'ofthe invention. In preparation of insertion, an impression is taken ofthe maxillary and premaxillary segments. A pair of plastic plates 49, 50are molded from the impression so that plates 49, 50 fit as nearperfectly as possible over the maxillary segments. in the moldingprocess, each plate 49, 50 is preferably molded around a respectiveoffset outer end portion 47, 48 of arms 43, 44 so that each respectivearm end and associated plate effectively become an integral unit. Inorder to mold the retaining staples 51 into plates 49, 50, the apparatusis placed so that the pivot points established by pins 41, 42 are overthe maxillary tuberosities with the segment arms 43, 44 in the fullyclosed position. The position of the retaining 51 is marked on thepalatal area and holes are then drilled into the plastic to accept thestaples 51 which in one embodiment have been made of 0.030 inch hightension stainless steel wire. The points of the staples are orientedlaterally and somewhat anteriorly so that expansion and retractionforces will be withstood. Prior to insertion, the appliance issterilized and with staples SI partly inserted into plates 49, 50, theapparatus is positioned in the mouth. Tongue and cheek'retractors areemployed-as needed during insertion of the invention apparatus 10. Whenapparatus 10 is in proper position so that plates 49, 50 mate with theproper maxillary bone area, staples 51 are driven level with plates 49,50 so that the apparatus becomes attached to the maxillary bone.

Next, saddle arrangement 20 has to be positioned in the desired spotalong the posterior premaxillary stern. Correct'location of premaxillarypin 53 is probably the most exacting procedure. The location is firstdetermined on a lateral dental radiograph of the septopremaxillarysegment and should preferably be in the basal premaxillary bone justposterior to the dental crypts and well anterior to thepremaxillo-vomeral suture. Measurements from the labial mucosal outlineand from the inferior mucosal outline to the marked position on theradiograph serve to establish the correct point for insertion of pin 53in the patient. Premaxillary pin 53 is obtained, for example, from an0.035 inch Kirschner wire and after being drilled through thepremaxillary bone, pin 63 is cut to the width of yoke 22. The coaxialshaft arrangement and the saddle arrangement are placed in the patientsmouth at the time of the original insertion of the expansion componentso that the T-shaped block 24 fits properly into housing 30. Yokeportion 22 is then engaged onto pin 53 by loosening screws 54, 55 andallowing slots 23', 23" to slide down over pin 53. Once in place, screws54, 55 are tightened thereby holding pin 53 between plates 20', 20" inslots 23', 23" by being clamped.

Now, by rotating knob 18, the maxilla bones may be gradually expanded asdesired. Once knob 18 is rotated, shaft 13 and integral universal jointassembly 11 are rotated. Universal joint 11 adapts the apparatus to adeviated septopremaxillary segments, and allows freedom of movement tothe premaxillary segment as it responds to tractional force. Forexpanding the maxillary segments, rotation of universal joint assembly11 causes shaft 27 to rotate and effectively moves T- shaped block 24back away from the interior of the mouth. As block 24 moves outward onshaft 27, arm

. ends 45, 46 tend tobe moved outward away from back plate 32. Sinceplates 49, 50 are molded integral with arm ends 45, 46 and since plates49, 50 are attached to the maxillary bone by staples 51, the outwardmovement of arm ends 45, 46 effectively expands the maxillary bonesegments. For example, a time schedule may be established for precise,measurable and controllable incremental changes in the expansion. Thecoil spring 17 which mounts between knobs l5 and 18 is compressed as thespace between the knobs decreases. Thus, spring 17 effectivelyprovides'a visual gauge and may be used to register, when in operation,the retraction force so that the load placed upon the premaxillary bonesmay be maintained with safe limits.

In a specific apparatus embodying the present invention, one turn ofknob 18 has been effective to expand the maxillary bone segments 1 mm.In the same embodiment, each rotation of knob 15 acts to retract saddlearrangement'20 and consequently to retract the ment of the cleftsegments which can be immediately followed through with agingivoperiosteoplasty at the same time as lip repair. Thus, bone can beexpected to grow into the cleft, unifying the upper jaw and stabilizingthe alignment of the maxillary arch. Such conditions are favorable forsubsequent growth to follow a normal pattern. In this way, it is hopedto avoid crossbite malocclusion and to render long term use of intraoralretention appliances unnecessary.

In summary, it can be seen that while the present invention apparatusoperates basically like the apparatus of the prior invention, a numberof improvements are evident. In particular, the universaljoint-blockhousing arrangement eliminates exposing mucosal tissue to theends of rotating shafts-as sometimes occurred with the prior apparatus.The universal joint also provides a much desired flexibility for meetingthe numerous kinds of cavity conditions encountered in infants. Aspreviously mentioned, the expansion apparatus of the present inventioncan be used independent of the retraction apparatus. Where retraction isof no particular interest, block 24 may be driven as illustrated in FIG.7. Thus, shaft 27 of FIG. 5 may be modified as represented by shaft 27'in FlG. 7 to include a recessed cap 55 with a recess 56, e.g.hexa'gon'al such that shaft 27' may be turned with a mating tool 57.This concept of using the expansion apparatus independently can befurther visualized by noticing that the expansion structure of FIG. 6when equipped with the intraoral drive structure of FIG. 7 representssuch an independent expansion device. Parents can be taught to make thenecessary adjustments with the FIG. 7 arrangement. Thus, treatment ofthe infant can proceed out of the hospital and at a substantialreduction of cost of the patient.

What is claimed is:

l. A mouth cavity maxillary bone correction apparatus, comprising:

a. a pair of elongated laterally spaced arm members having outer endportions residing in a common plane and adapted for intra-oral placementand securement to corresponding laterally displaced maxillary bone andopposite inner end portions adapted to extend intra-orally from suchsecurement;

b. a pair of plate means molded to conform and to be secured to ,saidbone, said plate means being secured to respective said arm member outerend portions thereby adapting such outer end portions to be secured tosaid bone;

c. housing means adapted to be intra-orally placed and formed byconnected walls and positioned between and rearwardlyof said platemeans, said housing providing integral outwardly extending portions formaking pivotal connections with medial portions of said arm membersenabling said arm members to be pivoted thereon, said housing wallsbeing formed to receive the respective said arm member inner endportions within said housing and to allow corresponding reciprocalmovements therein;

. screw block positioning means adapted to be intraorally placed andslidably mounted and confined within said housing such that saidpositioning means is isolated from any surrounding mucosal tissue duringuse thereof, said positioning means being between and having surfacesloosely engaged with said inner end portions of each of said arm membersto control the positioning thereof, said positioning means having ashaft drive enabling said inner end portions to be moved in an extraoraldirection to effect corresponding outward pivotal movements of said armmember outer end portions; and e. drive means including a drive shafthaving one inner end adapted to be intra-orally placed and connected todrive said positioning means by the turning of said drive shaft andhaving the other outer end thereof adapted to be extra-orally placed andadapted for finger engagement to effect rotation thereof whereby as saiddrive shaft is rotated in an appropriate direction and with respectivesaid arm member outer end portions secured to said bone through saidplate means, the lateral spacing of said bone may be increased to effectappropriate correction thereof.

2. An apparatus as claimed in claim 1 including a securing memberadapted to be intra-orally mounted and having an end portion adapted tobe fixedly secured to the premaxillary segment and an internallythreaded body portion formed integral therewith an auxiliary externallythreaded hollow shaft having one inner end adapted to be intra-orallyplaced and being rotatably mounted on and rotatably independent of saiddrive shaft, the opposite outer operating end of saidauxiliary shaftadapted to-be extra-orally placed and adapted for finger engagementthereof with the central portion of said auxiliary shaft beingthreadably mounted in said securing member body portion such that withsaid one end of the securing member pinned to said segment and with saidarm members secured to said bone, said segment and bone may be movedrelatively, bi-directionally, and incrementally for cleft lip and palatecorrection by corresponding extra-oral rotation of said outer operatingend of said auxiliary drive shaft.

3. An apparatus as claimed in claim 2 including a coil spring mountedbetween the respective outer ends of said drive and auxiliary shafts andbeing compressible according to the amount by which said auxiliary shaftis turned and the distance between said outer ends is decreased as avisual gauge of the amount of said correction.

4. An apparatus as claimed in claim 1 wherein said drive shaft outer endis formed as a removable drive shaft member adapted to be detachablysecured to the inner end of saiddrive shaft when needed for turning theinner end of said drive shaft.

5 An apparatus as claimed in claim 1 wherein said outer and inner driveshaft ends are connected through a universal joint.

6. An apparatus as claimed in claim 2 wherein said outer and inner driveshaft ends are connected through a universal joint.

7. An apparatus as claimed in claim 6 wherein for purposes of beingfixedly secured, said securing member end portion is adapted to receiveand to be clamped to a pin passing through said premaxillary segment.

QETEFIQATE GP @QECHGN Patent No. 3 27,664 Dated December 23, 1975Inventor(s) Nicholas G. Georgiade; Ralph A. Latham It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Immediately following the title the following paragraph was omitted inthe patent:

The invention described herein was made in the course of work privatelyfunded and also partially supported under a grant or award from theDepartment of Health, Education and Welfare. The United StatesGovernment is granted a nonexclusive, royalty free license to make, useand sell for governmental purposes under any patent issuing herefrom.

Col. 1, line 24, "cations" should be --cation--.

Col. line 52, "Krichner" should be --Kirschner--.

Col. 2, line 13, "posistion" should be --position--.

Col. line 31, -end-- should be inserted after "each".

001. line 25, "pine" should be -pins-.

Col.

Col. 3, line 41, "controll" should be -control-.

5, line 2, "plate" should be --plane-.

Col. line 42, -staples-- should appear after "ing" and before "51''.

C01. 6, line 17, "segments" should be -segment--.

heel of 2 UNITED STATES PATENT OFFICE ttTmcATE 0F CORRECTION patent NO3,927,664 Dated December 23, 1975 Inventor(s) Nicholas G. Georgiade;Ralph A. Latham It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Col. 7, line 1.1, the second appearance of the Word "of" should be -to-.

C01. 8, line 15, a comma should be inserted after "therewith".

Signed and Scaled this eighth Day of June 1976 qsmm Arrest:

RUTH C. MASON C. MARSHALL DANN Alreflinx Offifl" Commissioner affluent:and Trademarks

1. A mouth cavity maxillary bone correction apparatus, comprising: a. apair of elongated laterally spaced arm members having outer end portionsresiding in a common plane and adapted for intraoral placement andsecurement to corresponding laterally displaced maxillary bone andopposite inner end portions adapted to extend intra-orally from suchsecurement; b. a pair of plate means molded to conform and to be securedto said bone, said plate means being secured to respective said armmember outer end portions thereby adapting such outer end portions to besecured to said bone; c. housing means adapted to be intra-orally placedand formed by connected walls and positioned between and rearwardly ofsaid plate means, said housing providing integral outwardly extendingportions for making pivotal connections with medial portions of said armmembers enabling said arm members to be pivoted thereon, said housingwalls being formed to receive the respective said arm member inner endportions within said housing and to allow corresponding reciprocalmovements therein; d. screw block positioning means adapted to beintra-orally placed and slidably mounted and confined within saidhousing such that said positioning means is isolated from anysurrounding mucosal tissue during use thereof, said positioning meansbeing between and having surfaces loosely engaged with said inner endportions of each of said arm members to control the positioning thereof,said positioning means having a shaft drive enabling said inNer endportions to be moved in an extraoral direction to effect correspondingoutward pivotal movements of said arm member outer end portions; and e.drive means including a drive shaft having one inner end adapted to beintra-orally placed and connected to drive said positioning means by theturning of said drive shaft and having the other outer end thereofadapted to be extra-orally placed and adapted for finger engagement toeffect rotation thereof whereby as said drive shaft is rotated in anappropriate direction and with respective said arm member outer endportions secured to said bone through said plate means, the lateralspacing of said bone may be increased to effect appropriate correctionthereof.
 2. An apparatus as claimed in claim 1 including a securingmember adapted to be intra-orally mounted and having an end portionadapted to be fixedly secured to the premaxillary segment and aninternally threaded body portion formed integral therewith an auxiliaryexternally threaded hollow shaft having one inner end adapted to beintra-orally placed and being rotatably mounted on and rotatablyindependent of said drive shaft, the opposite outer operating end ofsaid auxiliary shaft adapted to be extra-orally placed and adapted forfinger engagement thereof with the central portion of said auxiliaryshaft being threadably mounted in said securing member body portion suchthat with said one end of the securing member pinned to said segment andwith said arm members secured to said bone, said segment and bone may bemoved relatively, bi-directionally, and incrementally for cleft lip andpalate correction by corresponding extra-oral rotation of said outeroperating end of said auxiliary drive shaft.
 3. An apparatus as claimedin claim 2 including a coil spring mounted between the respective outerends of said drive and auxiliary shafts and being compressible accordingto the amount by which said auxiliary shaft is turned and the distancebetween said outer ends is decreased as a visual gauge of the amount ofsaid correction.
 4. An apparatus as claimed in claim 1 wherein saiddrive shaft outer end is formed as a removable drive shaft memberadapted to be detachably secured to the inner end of said drive shaftwhen needed for turning the inner end of said drive shaft.
 5. Anapparatus as claimed in claim 1 wherein said outer and inner drive shaftends are connected through a universal joint.
 6. An apparatus as claimedin claim 2 wherein said outer and inner drive shaft ends are connectedthrough a universal joint.
 7. An apparatus as claimed in claim 6 whereinfor purposes of being fixedly secured, said securing member end portionis adapted to receive and to be clamped to a pin passing through saidpremaxillary segment.